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0 pointsschiffern3y ago0 comments

Note that, to minimize pollution from vehicle exhaust, you want to set your air to "recirculate". Unsurprisingly, the roadway is where vehicle pollution is most concentrated!

https://www.latimes.com/science/sciencenow/la-xpm-2013-sep-1...

Usually what I do is set it on recirculate, and then every ~10 minutes I periodically "flush" the CO2-laden interior air for a minute or so. Ideally, I'm able to do this "flush" when I'm away from a major city or high-traffic road (and not when driving behind a soot-spewing diesel bus/semi/garbage/cement truck).

I wish there were some way to automate this logic!

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(and yes, my dear observant reader, if I could recirculate "only" 90% of the exterior air it would achieve the same steady-state result, but modern cars got rid of the "slider" that lets you select a percentage of recirculate air... ::sigh::)

0 pointsschiffern3y ago0 comments

Note that, to minimize pollution from vehicle exhaust, you want to set your air to "recirculate". Unsurprisingly, the roadway is where vehicle pollution is most concentrated!

https://www.latimes.com/science/sciencenow/la-xpm-2013-sep-1...

I wish there were some way to automate this logic!

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0 comments

6 comments · 2 top-level

Retric3y ago· 2 in thread

That works for particulates but not gasses like carbon monoxide. You’re better off having the best filters you can get supplying fresh air constantly rather than constantly recirculating stale air.

schiffernOP3y ago

Carbon monoxide comes from vehicle exhaust, so the levels are still lower outside cities and off high-traffic roads. I'd rather recirculate my "stored up" clean air vs. pull in CO from the line of cars stopped ahead of me. I just involves being aware of the surroundings.

Ideally a controller would monitor the outside CO/PM and inside CO2 to control the recirculate door.

Retric3y ago

Location is generally less important than wind direction here, which you aren’t tracking.

Having a few internal and external sensors for various gasses could work, but it’s a surprisingly difficult problem.

1 more reply

sizzle3y ago· 2 in thread

I always crack my sunroof an inch and pull the shade forward go get some fresh air in recirculate mode so I’m not picking up crap from the engine bay.

How does the fresh air mode on the car not pull in CO gases from the engine bay? Surely a pleated cabin filter is not enough to stop it? Or does the air come from the manifold air intake?

bruckie3y ago

There should be very low levels of CO (at least from your car) in the engine bay, since exhaust is vented out the back of the car, and your engine shouldn't be leaking exhaust gases in other places. You might have some CO there from the cars in front of you, though.

lukevp3y ago

The air intake in the grille is only for the engine’s use. The fresh air intake is not in the engine bay, it’s typically at the base of the windshield.

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